essentially on a touchscreen hitting/clicking on the payment type menu is very tricky at the very least two clicks must be made in order to select payment type. if instead there were five buttons in a row for different payment types defaulting on cash you would need to press appropriate button and enter tendered value.

one of the aims of the new UI IMHO should be streamling the work flow eg lowering the number of clicks required to process transactions or the distance one needs to move ones finger for making a necessary click (the complete sale button). I operate a very small corner store and there are times of the day when speed of transactions makes all the difference.